diff --git a/drivers/pci/msi/api.c b/drivers/pci/msi/api.c
index 2d46a0cfd541..c8816db91e9c 100644
--- a/drivers/pci/msi/api.c
+++ b/drivers/pci/msi/api.c
@@ -112,6 +112,73 @@ int pci_enable_msix_range(struct pci_dev *dev, struct msix_entry *entries,
 }
 EXPORT_SYMBOL(pci_enable_msix_range);
 
+/**
+ * pci_msix_can_alloc_dyn - Query whether dynamic allocation after enabling
+ *			    MSI-X is supported
+ *
+ * @dev:	PCI device to operate on
+ *
+ * Return: True if supported, false otherwise
+ */
+bool pci_msix_can_alloc_dyn(struct pci_dev *dev)
+{
+	if (!dev->msix_cap)
+		return false;
+
+	return pci_msi_domain_supports(dev, MSI_FLAG_PCI_MSIX_ALLOC_DYN, DENY_LEGACY);
+}
+EXPORT_SYMBOL_GPL(pci_msix_can_alloc_dyn);
+
+/**
+ * pci_msix_alloc_irq_at - Allocate an MSI-X interrupt after enabling MSI-X
+ *			   at a given MSI-X vector index or any free vector index
+ *
+ * @dev:	PCI device to operate on
+ * @index:	Index to allocate. If @index == MSI_ANY_INDEX this allocates
+ *		the next free index in the MSI-X table
+ * @affdesc:	Optional pointer to an affinity descriptor structure. NULL otherwise
+ *
+ * Return: A struct msi_map
+ *
+ *	On success msi_map::index contains the allocated index (>= 0) and
+ *	msi_map::virq contains the allocated Linux interrupt number (> 0).
+ *
+ *	On fail msi_map::index contains the error code and msi_map::virq
+ *	is set to 0.
+ */
+struct msi_map pci_msix_alloc_irq_at(struct pci_dev *dev, unsigned int index,
+				     const struct irq_affinity_desc *affdesc)
+{
+	struct msi_map map = { .index = -ENOTSUPP };
+
+	if (!dev->msix_enabled)
+		return map;
+
+	if (!pci_msix_can_alloc_dyn(dev))
+		return map;
+
+	return msi_domain_alloc_irq_at(&dev->dev, MSI_DEFAULT_DOMAIN, index, affdesc, NULL);
+}
+EXPORT_SYMBOL_GPL(pci_msix_alloc_irq_at);
+
+/**
+ * pci_msix_free_irq - Free an interrupt on a PCI/MSIX interrupt domain
+ *		      which was allocated via pci_msix_alloc_irq_at()
+ *
+ * @dev:	The PCI device to operate on
+ * @map:	A struct msi_map describing the interrupt to free
+ *		as returned from the allocation function.
+ */
+void pci_msix_free_irq(struct pci_dev *dev, struct msi_map map)
+{
+	if (WARN_ON_ONCE(map.index < 0 || map.virq <= 0))
+		return;
+	if (WARN_ON_ONCE(!pci_msix_can_alloc_dyn(dev)))
+		return;
+	msi_domain_free_irqs_range(&dev->dev, MSI_DEFAULT_DOMAIN, map.index, map.index);
+}
+EXPORT_SYMBOL_GPL(pci_msix_free_irq);
+
 /**
  * pci_disable_msix() - Disable MSI-X interrupt mode on device
  * @dev: the PCI device to operate on
diff --git a/drivers/pci/msi/irqdomain.c b/drivers/pci/msi/irqdomain.c
index 8afaef10b939..deb1930b4e66 100644
--- a/drivers/pci/msi/irqdomain.c
+++ b/drivers/pci/msi/irqdomain.c
@@ -225,7 +225,8 @@ static const struct msi_domain_template pci_msix_template = {
 	},
 
 	.info = {
-		.flags			= MSI_COMMON_FLAGS | MSI_FLAG_PCI_MSIX,
+		.flags			= MSI_COMMON_FLAGS | MSI_FLAG_PCI_MSIX |
+					  MSI_FLAG_PCI_MSIX_ALLOC_DYN,
 		.bus_token		= DOMAIN_BUS_PCI_DEVICE_MSIX,
 	},
 };
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 243e48f79e82..68b14ba93df2 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -38,6 +38,7 @@
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/resource_ext.h>
+#include <linux/msi_api.h>
 #include <uapi/linux/pci.h>
 
 #include <linux/pci_ids.h>
@@ -1559,6 +1560,11 @@ int pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs,
 				   unsigned int max_vecs, unsigned int flags,
 				   struct irq_affinity *affd);
 
+bool pci_msix_can_alloc_dyn(struct pci_dev *dev);
+struct msi_map pci_msix_alloc_irq_at(struct pci_dev *dev, unsigned int index,
+				     const struct irq_affinity_desc *affdesc);
+void pci_msix_free_irq(struct pci_dev *pdev, struct msi_map map);
+
 void pci_free_irq_vectors(struct pci_dev *dev);
 int pci_irq_vector(struct pci_dev *dev, unsigned int nr);
 const struct cpumask *pci_irq_get_affinity(struct pci_dev *pdev, int vec);